The protein content of subretinal fluid (SRF) from idiopathic retinal detachment has been of interest since 1893 when Rählmann1reported a high percentage of albumin and concluded that this fluid must be a transudate from the choroidal vessels. Although for a time this idea became obscured by the popular concept that SRF came from the vitreous through ruptures in the retina, recent work has led to a revival of the transudate theory. In a previous paper,4we reported ascorbic acid findings together with protein studies which indicated a compound, blood/vitreous source, rather than a single origin, for subretinal fluid. The earlier literature on this controversy has been well reviewed by Magitot2and Longhena.3Both of these authors confirmed the observation that SRF contains more protein than does normal vitreous (Magitot, 17 cases; Longhena, 30 cases). Although more recent detachments in their cases tended to have low-protein